Linerless closures

ABSTRACT

A linerless closure cap comprising a top having integrally formed on the underside thereof inner and outer laterally deflectable sealing fins adapted to engage the generally rounded but inherently non-uniform mouth of a glass container adjacent the inner and outer peripheral portions thereof and to conform thereto and a compression ring stiffer and shorter than the sealing fins located therebetween and adapted to be compressed against the top of the container mouth when the closure cap is secured to the container.

United States Patent Demers et al.

[451 Oct. 29, 11974 LlNERLESS CLOSURES Inventors: Jacques Demers; RobertChar-tier,

both of Waterloo, Quebec, Canada Assignee: Consumers Glass CompanyLimited,

Rexdale, Ontario, Canada Filed: July 28, 1972 Appl. No.: 276,238

US. Cl. 215/344 Int. Cl B65d 53/00 Field of Search 2l5/D1G. 1, 40, 41,43;

References Cited UNITED STATES PATENTS 9/1935 21511210. 1 10/1956 Guinet215/D1G. 1

3,074,579 1/1963 Miller ..2l5/DIG,1 3,215,297 11/1965 Act0n.....

3,532,244 10/1970 Yates ..215/D1G.1

Primary Examiner--Dona1d F. Norton [57] ABSTRACT A linerless closure capcomprising a top having integrally formed on the underside thereof innerand outer laterally deflectable sealing fins adapted to engage thegenerally rounded but inherently non-uniform mouth of a glass containeradjacent the inner and outer peripheral portions thereof and to conformthereto and a compression ring stiffer and shorter than the sealing finslocated therebetween and adapted to be compressed against the top of thecontainer mouth when the closure cap is secured to the container.

4 Claims, 3 Drawing Figures LINERLESS CLOSURES FIELD OF THE INVENTIONThis invention relates to improvements in the means utilized to seal acontainer. In particular, this invention relates to improvements inlinerless closure caps for sealing a glass container which presentsspecial problems for sealing due to the fact that the rounded mouth ofthe container cannot be moulded precisely symmetrical but inherently hassome eccentricities or nonuniformity or irregularities relative to theaxis and also some non-uniformity or irregularity in the glass surfaceitself.

BACKGROUND OF THE INVENTION Linerless caps have been proposed but mostof these are for plastic containers wherein an axially symmetrical andaccurately flat mouth surface can be obtained and various forms ofsealing fins and rings formed on the underside of the cap have beenproposed to effect a seal with such containers. However, in the mouldingof glass the mouth of the container is required to be rounded and themoulding cannot be carried out with exact precision so that the mouth ofthe container may be somewhat out of round or lacking in precise axialsymmetry and the mouth surface itself may have a considerable unevennessboth in cross-section and around the mouth. These non-uniformities orirregularities make it extremely difficult to obtain a proper seal witha linerless cap and such caps proposed to date have not given the degreeof seal desired.

SUMMARY OF THE INVENTION It is therefore the object of this invention toprovide an inexpensive one-piece linerless cap moulded frompolypropylene or other similar suitable material, which will give anexcellent seal when used with a glass container.

According to the invention, the cap is provided on the underside thereofwith a sealing ring arrangement comprising inner and outer resilientlydeflectable sealing fins for engaging with and conforming to the innerand outer peripheral portions of the rounded mouth of the containerrespectively and at least one, (preferably one), central compressionring adapted to be compressed against the upper or crown surface of therounded container mouth, the resilient deflectable fins being longerthan the central compression ring and projecting downwardly therebeyond.

Further, according to the preferred embodiment of the invention therelatively longer inner and outer deflectable fins have respectivelydeflecting faces sloping inwardly and outwardly with respect to thecontainer axis and the relatively shorter central compression ring isrelatively stiffer than said fins and is of triangular cross section andpresents a central apex for initially substantially line contact withthe uppermost surface of the rounded container mouth as the closure isapplied to the container.

DETAILED DESCRIPTION OF THE DRAWINGS The invention shall now bedescribed and illustrated with reference to the accompanying drawingswherein:

FIG. I is a cross-sectional view of a linerless closure cap illustratingone embodiment of the invention.

FIG. 2 is an enlarged broken away view of the top left portion of thecross-sectional area. of FIG. 1.

FIG. 3 is a cross-sectional view of the linerless closure cap as securedto the top of a glass container.

DETAILED DESCRIPTION OF THE INVENTION According to the invention, aclosure cap 1 comprises a top 2 and skirt 3, having means 4 to securethe closure cap to the neck of the container I00. In the embodimentillustrated the securing means 4 comprises a male thread formed on theinternal surface of the skirt to mate with the helical recesses 5 of thecontainer although it will be appreciated other suitable fastening meansmay be employed.

As shown in FIG. 3 which is an enlargement of the neck 101 of thecontainer 100, the upper surface 102 defining the mouth of the containeris generally rounded but is not uniformly so because of the difficutiesof moulding the glass.

Not only is the upper surface I02 not uniformly rounded but the neck 101itself may not be precisely centered on the axis of the container sothat the inner peripheral portion 103 and the outer peripheral portion104 of the container mouth may beat varying distances from the containeraxis around the container mouth.

In addition to the lack of uniformity in the curvature of the containermouth in vertical cross section, there will also be a corresponding lackof uniformity in the surface 102 along a circular path centered on thecontainer axis and traced on the surface 102.

This lack of uniformity or irregularity in the container mouth portionrenders the usual form of linerless caps or closures ineffective for thepurpose of sealing the container. The present invention, however, hasbeen found to provide a cap giving a highly effective seal when usedwith containers whose mouth configurations vary over the entire gambitof acceptable container mouldings. That is the particular sealingconfiguration provided on the inside of the cap or closure is capable ofaccommodating all such variations in vertical cross section, crown orsurface contour and axial eccentricity.

As shown particularly in FIGS. 2 and 3, the sealing arrangementcomprises an outer annular sealing ring or fin 6., an inner annularsealing ring or fin 7 and an intermediate or central compression sealpreferably in the form of a single ring 8 which is substantially shorterand stiffer than the sealing fins 6 and 7, the arrangement being suchthat a line joining the apexes 6a, 8a and 7a of the rings 6, 8 and 7describe a surface generally corresponding to the rounded upper endsurface 102 of the container mouth.

The outer sealing fin 6 is formed with an inner outwardly slopingsurface 9 and an outer preferably substantially vertical surface 10. Theangle defined by the intersection of the surfaces 9 and 10 is preferablyof the order of about30 so that this outer fin 6 is relatively slenderand therefore quite readily deflected when its sloping surface 9contacts the upper surface 102 of the container mouth.

Similarly the inner fin 7 has its outer surface 11 with respect to theaxis of the container sloped corresponding to the surface 9 of the outerfin 6. The inner surface 12 of fin 7 is also preferably vertical andagain the intersection of the surfaces 11 and 12 preferably forms anangle of about 30 to provide a slender readily deflectable sealingmember for displacement over the surface 102 of the container when thesloping surface 11 contacts the container mouth.

The intermediate ring 8 is \/-shaped and preferably defines in crosssection an equilateral triangle with the side walls 13 being inclined toeach other at approximately 60 so that the apex 8a is blunter than theapexes 6a and 7a and is centered between the sides 13 so that as theapex 7a contacts the container surface 102, the compression ring 8 willbe compressed rather than deflected. When the closure or cap formedaccording to the invention is applied to the container, the apexes 6aand 7a of the sealing fins 6 and 7 will first contact the containersurface 102 and depending upon the eccentricity of the container neck,the fins 6 and 7 on further advancement of the closure towards theclosed position will be deflected towards or over the outer and innerperipheral portions 104 and 103 respectively of the container mouth. Asshown in FIG. 3 the eccentricity of the container mouth is such that theinner fin 7 has been displaced as guided by the sloping or cam surface11 to substantially cover the inner peripheral mouth portion 103. Itwill be understood that the fin 7 will have sufficient resiliency sothat while it is deflectable under the camming effect of theinterengagement of the surface 11 with the surface portion 103, it willnevertheless have sufficient resistance to displacement that it willpress against the surface 103 as it tends to recover towards its normalunrestained portion shown in FIG. 2.

[n the illustration in FIG. 3 it will be seen that the outer fin 6 hascontacted the upper surface 102 of the neck inwardly of the outerperipheral surface portion 104 and as the closure is advanced, the outerfin 6 will be deflected more along the top of the surface 102 ratherthan down over the edge or outer peripheral portion 104 of this surface.Nevertheless, the inherent resiliency of the fin 6 will be such as tocause it to tightly conform to the surface 102 as it wipes over thesurface during displacement.

It will be understood that the deflection of the fins 6 and 7 willcontinue until the compression ring 8 contacts the upper surface 102 ofthe container mouth and because the apex8a of the compression ring 8 iscentrally located, further advancement of the closure will causecompression of the compression ring. The first contact of thecompression ring with the surface 102 will provide a line contact withthe high spots on the surface and as the container is advanced, theapex8a will be deformed into a flap at the high points of the surface102 until a line contact is established with the low points of thesurface, the ring having sufficient compressibility and sufficientresiliency that for all normal mouth variations a complete seal can beobtained on the surface 102 completely around the mouth, it beingunderstood that some portions of the compression ring 8 will becompressed more than other portions. It will also be understood thatwhen the compression ring 8 has been substantially fully compressed itforms a stop limiting further cap closing movement.

The seal obtained with the sealing arrangement ofthe present inventionhas been found very effective and it appears that, during thecompression of the compression ring 8 as the cap is closed tight downagainst the top of the container, air is compressed in the chambers 14defined between the compression ring 8 and the fins 6 and 7 and themouth surface 102. This air acting under pressure against the slopingdeflecting surfaces 9 and 11 has the tendency to deflect the fins andexhaust therebeneath. Air attempting to move back into the chambers 14on the other hand, will press against the outer generally verticalsurfaces 10 and 12 and act to force the fins into tighter sealingengagement with the surface 102, rather than enter the chambers. Thus,any tendency of the cap to contract or any slight unloosening of the capdoes not immediately break the seal across the top of the container butrather appears to increase the intimate fin to container surface contactand the closure seal remains effective indefinitely, regardless of theirregularities or non-uniformities of the container mouth.

While the preferred embodiment of the invention has been particularlydescribed, it will be understood that variations in detail as apparentto those skilled in the art may be made without departing from thespirit of the invention or scope of the appended claims.

I claim:

1. In combination, a glass container whose mouth configuration has agenerally rounded upper edge or crown which in vertical section curvesdownwardly in opposite direction from a generally central crest portion,but which varies in vertical cross-section, crown surface contour aroundthe mouth and eccentricity, and a linerless closure cap suitable forsealing the mouth of said container, said closure cap comprising a skirtand top, said skirt having means for securing said cap to the neck ofsaid container, said top having on the underside thereof an integralouter annular resilient readily deflectable sealing fin disposed tocooperate with the downwardly curving portion of the container mouthcrown outwardly of the central crest portion, said outer fin having aninner surface sloping outwardly of the fin axis from adjacent to saidtop to the free edge thereof for displacing said outer fin outwardly oncontacting the downwardly and outwardly curving crown portion, anintegral inner annular resilient readily deflectable sealing findisposed to cooperate with the downwardly curving portion of thecontainer mouth crown inwardly of the central crest portion, said innerfin avin an, pater s es t rin inwa y o h fi axis from adjacent to saidtop to the free edge thereof for displacing said inner fin inwardly oncontacting the downwardly and inwardly curving crown portion, and anannular resilient compression ring stiffer and of lesser depth than saidouter and inner fins and resistant to lateral deflection, locatedbetween said fins, said compression ring terminating in a V" apex andadapted to contact the central crest portion of the rounded crown whenthe closure is applied to the mouth of the container, whereby uponcontact of the compression ring with the crown surface, a line contactis first provided between the compression ring and the high spot on thecrown crest and a wiping contact is provided between said fins and crownon opposite sides of said crown crest as said fins are deflected by saiddownwardly curving crown portions, and as the closure is advanced to asealing configuration, said compression ring is compressed into flats atthe high spots of the crown crest until at least a line contact isestablished with the low spots of the crown crest to define two isolatedchambers one between the compression ring, the crown surface, and theinner fin, and the other between the compression ring, the crown surfaceand the outer fin, and said fins are deflected to first exhausttherebeneath air compressed in said isolated chambers and to said outersubstantially vertical outer surface of said outer fin of said linerlessclosure cap and the angle between said outer surface sloping inwardlyand said inner substantially vertical inner surface of said inner fin ofsaid linerless closure cap are each about 30.

4. The combination as claimed in claim 3 in which the V apex of saidcompression ring defines an angle of about

1. In combination, a glass container whose mouth configuration has agenerally rounded upper edge or crown which in vertical section curvesdownwardly in opposite direction from a generally central crest portion,but which varies in vertical crosssection, crown surface contour aroundthe mouth and eccentricity, and a linerless clsoure cap suitable forsealing the mouth of said container, said closure cap comprising a skirtand top, said skirt having means for securing said cap to the neck ofsaid container, said top having on the underside thereof an integralouter annular resilient readily deflectable sealing fin disposed tocooperate with the downwardly curving portion of the container mouthcrown outwardly of the central crest portion, said outer fin having aninner surface sloping outwardly of the fin axis from adjacent to saidtop to the free edge thereof for displacing said outer fin outwardly oncontacting the downwardly and outwardly curving crown portion, anintegral inner annular resilient readily deflectable sealing findisposed to cooperate with the downwardly curving portion of thecontainer mouth crown inwardly of the central crest portion, said innerfin having an outer surface sloping inwardly ofthe fin axis fromadjacent to said top to the free edge thereof for displacing said innerfin inwardly on contacting the downwardly and inwardly curving crownportion, and an annular resilient compression ring stiffer and of lesserdepth than said outer and inner fins and resistant to lateraldeflection, located between said fins, said compression ring terminatingin a ''''V'''' apex and adapted to contact the central crest portion ofthe rounded crown when the closure is applied to the mouth of thecontainer, whereby upon contact of the compression ring with the crownsurface, a line contact is first provided between the compression ringand the high spot on the crown crest and a wiping contact is providedbetween said fins and crown on opposite sides of said crown crest assaid fins are deflected by said downwardly curving crown portions, andas the closure is advanced to a sealing configuration, said compressionring is compressed into flats at the high spots of the crown crest untilat least a line contact is established with the low spots of the crowncrest to define two isolated chambers one between the compression ring,the crown surface, and the inner fin, and the other between thecompression ring, the crown surface and the outer fin, and said fins aredeflected to first exhasut therebeneath air compressed in said isolatedchambers and to thereafter establish a sealing contact of appreciablewidth with the downwardly curving crown portions on either side of thecrown crest around said container mouth.
 2. The combination as claimedin claim 1 in which the inner surface of the inner fin and the outersurface of the outer fin of said linerless closure cap are substantiallyvertical.
 3. The combination as claimed in claim 2 wherein the anglebetween said inner surface sloping outwardly and said outersubstantially vertical outer surface of said outer fin of said linerlessclosure cap and the angle between said outer surface sloping inwardlyand said inner substantially vertical inner surface of said inner fin ofsaid linerless closure cap are each about 30*.
 4. The combination asclaimed in claim 3 in which the ''''V'''' apex of said compression ringdefines an angle of about 60*.